The frontroll is best learned by hitting the wake that is opposite of the wake you throw your best backroll from. This is true because the motions are similar.

Make a hard cut toward the wake. When the tip of your board touches the wake, flatten out and launch as you would a normal big wake jump. It's important to flatten out before you launch to maintain your center of balance.

Now, throw your head and shoulders as you would a backroll from the other wake. At the same time throw the tip of your board down. This will assure that you roll, rather than having the board just fall behind you. If that happens, you'll crash. Keep the handle close to your waist and you'll come around.

I can't get the full rotation. Wait a little longer before you throw the roll.

I roll but land sideways. You're not throwing the board down enough and letting it get behind you.